A buyer and a seller are haggling over the price of a new, more fuel efficient car. They can’t quite agree on a price or the ratio of cash to trade-in-value but they are both motivated to make a deal.
Buyer: Tell you what…Here’s 1/3 of the money up front. Give me the car and we’ll work out the rest tomorrow.
Seller: How do I know you’ll come back tomorrow?
Buyer: Because I’ll sign a deal today that says we’ll finish negotiating the price by tomorrow noon.
Seller: What if we can’t agree by then? How do I know I’ll get something for the car.
Buyer: If we can’t agree by noon I’ll pay full sticker for the car. But before that you have to agree to work on the deal all morning, just the two of us.
Buyer: One more thing…I’m tapped. I won’t have the cash until I get paid next month.
Seller: That’s a long time.
Buyer: That’s what I need.
A deal to this effect is written up and signed by both parties. The next day, despite hours of negotiating in an enclosed room, there is no agreement. The buyer leaves and a month later her returns.
Buyer: You don’t really expect me to pay full sticker, do you? We were supposed to reach a better deal by now.
Seller: Here’s the contract you signed. I kept my end of it. I negotiated all day and gave you a whole month off. It’s time to pay up.
Buyer: I’m going to tell your boss about the terrible, unfair deals you make.
Seller: This was your idea!
Buyer: It wasn’t supposed to happen. It was just a mechanism to make us negotiate harder.
Seller: Well, here’s your signature and the mechanism says the price is full sticker.
Buyer: It’s not fair. I’ll go over your head unless you tear that up and give me the best offer you made last month.
The buyer (whose name is Barack) is attempting to renegotiate the deal after the fact. To use a sports metaphor, he’s moving the goalposts.